The huge festival - which started on Friday in Indio - will see 184 acts take to the stage over two weekends.
Beyonce wasn't due to be one of them. Nonetheless, she joined Solange on stage yesterday to do a perfectly choreographed dance routine - sending the crowd wild.
Mother-of-two Beyoncé, who's only just returned from the Dominican Republic where she was celebrating her sixth anniversary with hubby Jay, wore flower print crop top and matching skirt dress and trilby, while Solange took to the stage in an orange jumpsuit.
Among the headliners this weekend are hip-hop duo Outkast, dance band Bastille and British singer Ellie Goulding.